Gear-shift-locking mechanism



A. v. AND E. s. BERRY. GEAR SHIFT LOCKING MECHANISM.

APPLICATION. FILED JUNE 27,192]- 1,407,45 8, Patented Feb. 21, 1922.

1212287 55 Belly entries stares ARTHUR-V; BERRYAND BLT/[ER S; BERRY, OF HEBRON, OHIO.

' eEAn-sHIr'rocmno' MECHANISM.

ii ,iil-tAfi Applicationrfiled June 27,

and has for its primary object toiproi 'ide a structure which Wlll effectively ser e to preclude the shifting of such levers when one of said levers occupies a position maintaining gearing governed'thereby in intermeshed engagement with a gear train.

Another object of the invention resides in providing safety locking mechanism of the character aforesaid upon farm tractors, and to combine the said mechanism with the driving and reverse gear controlling levers of a tractor, in order that one of said levers Will be restrained from movement when the other cooperative lever occupies an active position maintaining the gear controlled thereby in driving relation with the gear train of the tractor, the arrangement being such that it will be impossible for both the driving and reverse gears of the tractor to be simultaneously locked in mesh with associated gearing, as may readily happen, and with disastrous results, when the locking mechanism is not employed.

V For a furtherunderstanding of the inven: tion, reference is to be had to the following description, and to the accompanying draw ing, wherein similar characters of reference denote like and corresponding partsthroughout the several viewsthereof. In said drawing: Y

Figure l is'aside elevation of a tractor, disclosing more particularly the drive gearing therefor and the manually operated levers for governing the operation of the gearing. i

Figure 2 isa vertical sectional view taken through the lever construction, and illustrating the locking mechanism, comprising the present invention, associated therewith.

Figure 8 is a transverse horizontal sectional view taken through the lever con% struction and-the associated locking mechanism. H 7

Referring more particularly to the de tailsof the invention, the numeral 1 designates a farm tractor, which is formed to in- Specification of Letters-Patent. Pgyfgn'fged Fei 21 199.2

1921. Serial No. 480,515.

'clude a main horizontally extending frame 2 and a supplemental. frame 3, which is slidable upon the main frame, the said supplemental frame being adapted to carry the power plant a of the tractor in the usual manner comn'ionto this particular type of tractor. A drive shaft 5 leading from the power plant is equipped with a spur pinion 6, which, upon movement on the part of the supplemental frame is designed to be moved into engagement with the teeth of a relatlvely enlarged intermediate gear 7. This latter gear is carried by a shaft 8, suitably journaled in connection with the main frame, and the shaft 8, in turn, is equipped with a spur pinion 9, which is constantly in mesh with. an enlarged crive gear 10. This gear is adapted to be rigidly connected with the rear drive wheels, not shown, of the tractor, which are mounted upon the usual axles 11, projecting from fixed pedestals 12 carried by the under part of the main frame 2. By this construction, it will be apparent that when the frame 3 is shifted bodily, the pinion 6 will be moved into or out of mesh ing engagement with the intermediate gear 7, thus controllingthe forward movement of the tractor.

Also arranged for cooperation with the intermediate'gear 7 is the reverse gear 13 of the tractor. This gear is pivotally mounted as at 14 for swinging movement, and by being'oscillated about the pivot i l, the said reverse gear is capable of being moved into or out of driving relation with respect to the intermediate gear, the said reverse gear being driven in any suitable manner from the engine or power plant 4. To govern the positions of the reverse gear, there is provided a bell crank 15, which is pivotally supported in any suitable manner from the main frame 2, and is also connected with an arm 16 extending to the axis of the gear 13, and a manually operated link 17 has its forward end pivotally connected with the bell crank, whereby upon movement on the part of the said link, the bell crank will be oscillated to throw the reverse gear into or out of meshing engagement with the intermediate gear 7 To govern theselective actuation of both the forward drive pinion 6, and the reverse gear 13,the particular form of tractor disclosed employs a pair of operating levers l8 and 19, the former being utilized for the purpose of governing the positions of the 22, having notches 23 and 24: formed therein.

The levers 18 and 19 are pivotally connected as at 25 with the bracket 20, and beneath its pivot 25 the lever 18 is pivotally connected as at 26 with the slidable frame 3. It will be seen that by oscillating the lever 18, the supplemental frame may be longitrain may be readily governed.

tudinally adjusted to more its driving pinion or pinions 6 into or out of meshing engagement with. the gear train. The lever 19 also has its lower end pivotally connected as at 27 with the link 17, so that by the oscillation of the lever 19, the operative positions of the reverse gear with respect to the gear The said levers are maintained in their various operative positions by use of the ordinary spring pressed latches 28, which are designed to be received within the notches 23 and 2 1 so that the levers may be locked inconjunction with the stationary bracket 20. It will be understood that the latches 28 have their operation controlled by the ordinary lift levers 29, which are pivotally connected as at 30 to the upper ends of the levers 17 and 18 contiguous to the handles 31 thereof.

The construction so far described is that commonly employed upon a well known make of farm tractor, and the present invention consists essentially in providing a safety lock mechanism for governing the operation of this mechanism. It will be manifest that by reason of the construction described, it is possible, either by carelessness or confusion on the part of the tractor operator, for both the reverse and drive gear to mesh with the intermediate gear 7 at the same time, since there is nothing to prevent one lever from being operated when the other lever occupies a position maintaining its respective gear in mesh with the gear train. This accidental simultaneous meshing of both the gears 6 and 13 with the intermediate gear frequently happens, because of the relationship between the levers 18 and 19, and naturally results in gear breakage, break downs and other unnecessary delay in the operation of the tractor. By the present invention a locking mechanism is provided whereby it will be impossible to operate either one of the levers .18 and 19 when the other lever occupies a position maintaining its respective gear in mesh with the intermediate gear. a j

r This end is accomplished bythe agency of reversely positioned spring operated bolts 32. These bolts are mounted for sliding movement on a horizontal plane and are supported in conjunction with the sidewalls 21 of the bracket 20. Lach bolt is formed to include an enlarged head 33, having a beveled end 34, the latter being received within an elongated opening 35 provided in one of the sides 21. The opposite end of each bolt is provided with a reduced shank 36,which is also adapted to be received within an opening 37 formed in the opposite wall of the bracket, and a spring 38 surrounds each of the shanks 36 and is confined-between'the enlarged head 33 of each bolt and one of the side walls 21. Then, each of the levers 18 and 19 is provided with an opening'39, situated to register with the bolts 32 and adapted for cooperation therewith. By this construction it will be obvious that when the levers 18 and19 occupy the neutral positions, shown in Figure 1, the same may be freely moved to their active positions with out hindrance on the part of the bolt mechanism. This free movement of the levers can be. effected because of the fact that the diameter of the openings 39 provided in said levers will not admit of the entrance of the spring pressed bolt heads 33 therein, the said bolts being retained in retractedor inactive positions, with. the reduced shank ends'thereof projecting to a point where they will be out of engagement with the levers proper. However, if, for example, the lever 18 is moved to an active position, throwing the spur pinion 6 in mesh with the intermediate gear 7, the said levers will then be positioned side by side, which will result in forcing one of the latch bolts longitudinally against the resistance by its spring 38, thus causing the reduced end of the said bolt to be forced into the opening 39 of the reverse lever 19 and thereby locking the said reverse lever against movement during the retension of the lever 18 in "its active position. It will thusbe manifest that it will be impossible to move the reverse lever from a neutral position when the lever 18 is in an active position. The relative arrangement of the lock boltsis such that the same operation will take place when the. reverse lever is moved to assume an ctive, position, in that the latch bolt governed thereby will lock the lever 18 againstmovement. This construction provides asimple and positive structure for governing the operation of the throw levers, and effectively precludes any careless or accidental movements on the part of the levers that would tend to simultaneously throw both the drive and reverse pinions in mesh with the intermediate gear. serves to prevent damage to thedrivegearlocking mechanism itself is: of an extremely simple nature and may be readily applied ing of the tractor and eliminates expense, 7

to a tractor of the type set forth without changing or altering the usual construction thereof. I What is clalmed 1s:

1. A safety gear shift mechanism com-V prising a pair of pivotal levers, supporting walls arranged on opposite sides of said le-' path of movement of said levers, whereby the said bolts will be slidably projected when engaged by said levers, and each of said levers being provided with an opening capable of receiving reduced shank ends of said bolts when the latter are slidably projected by being engaged by said levers.

2. A safety locking mechanism for gear shift levers, the combination with a pair'of pivotally' mounted levers, of a fixed support arranged contiguous to said levers, and

spring actuated bolts carried by said support and capable of being engaged with said levers whereby when one of said levers occupies an active position, the other lever will be positively retained against movement in an inactive position. V

'3. In locking mechanism for gear shift 7 levers, the combination with a pair of pivotally mounted levers, of a fixed support ar' ranged contiguous to said levers, said support being provided with openings capable of aligning with cooperative openings provided in said levers, and. reversely positioned spring operated bolts slidably carried by said support and arranged for cooperation with said levers, whereby when one of said levers occupies an active position, the same will force one of said bolts into the locking opening provided in the inactively positioned lever, thereby precluding movement on the part of said latter lever.

4. In a tractor, the combination with the gear shift levers thereof, of a locking mechanism for said levers, including a stationary support arranged contiguous to said lever, said support being provided with bearings capable of aligning with openings provided in said levers, reversely positioned bolts arranged with sliding movement within said bearings and cooperative with said levers, said bolts being formed to include relatively enlarged heads and reduced shanks, the openings and said levers corresponding substantially to the diameter of said shanks, and springs operating to normally project the enlarged heads of said bolts into the path of movement of said levers.

5. In a tractor, the combination with the gear shift levers thereof, of a locking mechanism for said levers, including a fixed support arranged contiguous to said levers, said ARTHUR V. BERRY. ELMER S BERRY. 

